Drum for a creasing device

Abstract

A drum for a creasing device, a resilient creasing ring and method are provided. The drum includes first and second drum parts that cooperate with one another to define a circumferential channel of the drum a base and two side wall for receiving a resilient creasing ring. At least one of the side walls includes recess for receiving a portion of the resilient creasing ring such that the resilient creasing ring cannot be removed radially from the channel. The creasing ring may be continuous or a split ring. A method of mounting the creasing ring includes mounting the resilient creasing ring on a first drum part and axially sliding a second drum part into cooperation with the first drum part to mount the creasing ring within a channel formed therebetween.

1. A resilient creasing ring for a creasing device, the ring comprising a radially projecting creasing rib and at least one lateral rib for location in a recessed side wall of a channel in a drum of the creasing device, and an outwardly facing traction surface adjacent to the creasing rib. 
   
   
     2. A resilient creasing ring for a creasing device, the ring when viewed in cross-section having the general form of a rectangle defining a flat inner surface forming a seat and a flat outer surface forming a traction surface from which a creasing rib radially projects. 
   
   
     3. A resilient creasing ring according to  claim 2 , wherein the outer surface has a first width and the creasing rib has a second width, parallel to the first width, that is less than the first width. 
   
   
     4. A resilient creasing ring according to  claim 3 , wherein the flat inner surface and the flat outer surface defines a first height therebetween and creasing rib extends a second height from the flat outer surface, the first height being greater than the second height. 
   
   
     5. The resilient creasing ring of  claim 3 , wherein the flat inner surface has a third width, the third width being equal to the first width. 
   
   
     6. A resilient creasing ring according to  claim 2 , wherein a first portion of the traction surface is on one lateral side of the creasing rib and a second portion of the traction surface is on an opposite lateral side of the creasing rib, such that the creasing rib is bounded on both sides by the traction surface, the first and second portions being substantially co-planar. 
   
   
     7. The resilient creasing ring of  claim 6 , wherein the cross-section having the general form of a rectangle when viewed in cross-section includes first and second lateral side surface portions that extend radially inward toward the flat inner surface from opposite edges of the outer flat surface. 
   
   
     8. The resilient creasing ring of  claim 7 , wherein the first and second lateral side surface portions are parallel to one another and extend perpendicular to the inner and outer flat surfaces.